Improvement in mortising-machines



UNITED STATES PATENT OFFICE.

JOHN DRIVER, on MARYSVILLE, CALIFORNIA.

IMPROVEMENT IN MORTISING-MACHINES.

Specification forming part of Letters Patent No. 140,257, dated June 24, 187 3; application filed April 10, 1873.

To all whom it may concern:

Be it known that I, JOHN DRIVER, of Marysville, Yuba County, State of California, have invented an Improved Mortising-Machine; and I do hereby declare the following description and accompanying drawings are sufficient to enable any person skilled in the art or science to which it most nearly appertains to make and use my said invention or improvement without further invention or experiment.

My improvement in mortisin g-machines consists in the employment of a chain-saw and its adjustment for cutting the mortise, by which the work can be neatly and quickly accomplished.

In order to explain my invention, so that its construction and operation can be readily understood, reference is had to the accompanying drawings forming a part of this specification, in which- Figure 1 is a front elevation of my mortising-machine. Fig. 2 is a back view of the supporting-plate f. Fig. 3 is a top view of the adjusting-plates. Fig. 4 is an enlarged view of the teeth of the chain-saw.

A represents the frame of an ordinary mortising-machine. B is the table upon which the wood to be mortised is placed, and O the treadle which lifts the table so as to bring the wood in contact with the mortising-tool. A shaft, (1, is supported at a right angle to the table B, in boxes upon the top of the frame A, so that one end will project over the front of the frame, while the opposite end projects to the rear, and is provided with a loose and fixed pulley in the ordinary manner of applying pulleys to shafts. The front end has a chain-pulley, K, secured to it. To the front side of the frame A, below the end of the shaft d, I secure a metal casting, f, which is provided with a vertical dovetail groove in its front face, through the bottom of which a slot extends almost from end to end of the block. A metal block, g, is made to fit in this dovetail groove, and has a lug, h, on its inner side, which passes through the slot in the block. (Fig. 2.) A long screw, i, passes vertically up through the block 9 and lug h to fix the dovetail block 9 at the desired point. J is a thick metal plate, which is provided with a deep groove, 0, in each of its edges, and to the lower end of which a grooved collar, 7, is secured, so that it can revolve freely. The front face of the dovetail block 9 is provided with a deep groove, into which a rib or projection, t, on the back of the plate J fits. A screw, n, then secures the plate J to the dovetail block, as shown. It will be seen that the upper pulley K, and plate J with. its end roller 1', are in the same vertical plane. An endless link-chain, s, is then mounted upon the two pulleys K r, the links of which are formed with a projecting back, which will travel in the. grooves in the edges of the plate J and roller 1", in order to guide the chain and keep it in place, the chain-pulley K serving to drive it. Each link of the chain 8 is provided with a cutting-tooth, a, which is similar to a sawtooth, so that as the chain travels around the lower pulley r it will cut a mortise in the piece of wood which is pressed against it, which is just as wide as the two opposite moving sides of the chain are far apart. The chain .9 may be made as wide as desired by multiplying" the number of links, and the teeth may be constructed in various ways.

By employing this endless mortising-tool the mortise will be cut much cleaner than when a chisel is used, as the chain will go entirely through the mortise and leave no cores to be drix'en out, as in ordinary hand-mortising.

Having thus described my invention, what Witnesses:

H. B. WILLIAMsoN, G. B. HARNISH. 

